Znorg. Chem. 1993,32, 3923-3927
3923
Chalcogenide Substitution Reactions Jonathan M. Mcconnachie, John C. Bollinger, and James A. Ibers' Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3 1 13
Received January 5, I993 The feasibility of preparing tellurometalates from selenometalates has been demonstrated by the preparation of the compounds [PPh414[Ni4Te4(Te&(Te3)4] and [PPh4I4[Pt4Te4(Te3)6] from the reactions in DMF of TePEt3 with [PPh4]2[Ni(Se4)2] and [PPhp]z[Pt(Se4)3],respectively. The NEt4+ salt of the [Pt4Te4(Te3)61C ion could also be isolated from the reaction of R(xan)z with Li2Te and Te in DMF. The anion [Ni4Te4(Te2)2(Te3)4]' has a N4Te4 cubane core, with pairs of Te22- chains bridging NiIV atoms on opposite faces of the core and four Te3z-chains bridging the NiIVatoms on the remaining cubane faces. The anion [Pt4Te4(Te,),]~SSeSSeS a Pt4Te4 cubane core and has six Tep2-chains bridging PtIV atoms on the cubane faces. In the cubane anions each metal atom is in a distorted octahedral environment, being coordinated by three Te atoms in the cubane framework and by three Te atoms in chains that bridge to the other three metal atoms. Unit cell data (-163 "C): [PPh4]4[Ni4Te4(Te2)2(Te3)4], space group DLPan2, a = 18.925(3) A, c = 17.155(3) A, V = 6144(2) A3, Z = 2; [PPh4]4[Pt4Te4(Te3)6], space space group C6,-R3c, a = 27.024(3) A, a = 59.91(2)O, V = 13954(3) A3, Z = 4; [NEt4]4[Pt4Te4(Te3)6]-2DMF, a = 15.685(3) A, b = 40.103(8) %I, c = 15.330(3) A, 6 = 119.10(3)', V = 8426(3) A3, Z = 4. group C2h-P21/~, 3 with Se atoms to form [M3S(SSe)3X6l2-(M = Mo, W; X = C1, Br):
Introduction The chemistry of chalcogen-containing compounds has been theobject ofconsiderableinterestover thelast 25 years.'-' Several different sources of chalcogen have been used to make soluble chalcogen-containingcompounds. The simplest sources are the elements, which are reduced by another reactant to Q2- (Q = S, Se, Te).8.9 The most common source is a solution of polychalcogenide, Qnr,10-12 prepared by dissolving hydrogen chalcogenide or an alkali metal chalcogenide and elemental chalcogen in NH3(l), DMF, THF, CHsCN, or other solvents. Chalcogen delivery agents, such as phosphines, QPR3,l3J4 and organotrisulfides, (RS)2S,l5 have also been used. In addition, silyls, (R3Si)2Q,1"18 have been employed, generally to replace 0 or C1 with S,Se, or Te. In an important variation on this approach19 SePPh3 was used to replace three S atoms from [M3S(S2)3X612(1) Miiller, A.; Diemann, E.; Jostes, R.; Bdgge, H. Angew. Chem., Inr. Ed. Engl. 1981, 20, 934-955. (2) Miiller, A,; Diemann, E. Adu. Inorg. Chem. 1987, 31, 89-122. (3) Draganjac, M.; Rauchfuss, T. B. Angew. Chem.. Inr. Ed. Engl. 1985, 24, 742-7 5 7. (4) Ansari. M. A.: Ibers, J. A. Coord. Chem. Rev. 1990, 100, 223-266. (5) Kanatzidis, M; G. Comments Inorg. Chem. 1990, 10, 161-195. (6) Kolis, J. W. Coord. Chem. Rev. 1990, 105, 195-219. (7) Barbaro, P.; Bencini, A.; Bertini, I.; Briganti, F.;Midollini, S . J. Am. Chem. Soc. 1990, 112,7238-7246. (8) Zakn, A.; Berg, D. J. Acta Crysrallogr., Secr. C: Cryst.Srrucr. Commun. 1988,44, 1488-1489. (9) Yu, S.-B.; Papaefthymiou, G. C.; Holm, R. H. Inorg. Chem. 1991,30, 3476-3485. (10) Muller, A,; Sarkar, S.;Bhattacharyya, R. G.; Pohl, S.; Dartmann, M. Angew. Chem.. Int. Ed. Engl. 1978, 17, 535. (1 1) Ansari, M. A.; Mahler, C. H.; Chorghade, G. S.;Lu,Y.-J.; Ibers, J. A. Inorg. Chem. 1990, 29,3832-3839. (12) Homer, W. A.; ONeal, S.C.; Kolis, J. W.; Jeter, D.; Cordes, A. W. Inorg. Chem. 1988, 27,969-971. (13) Steigerwald, M. L.;Rice, C. E. J. Am. Chem. Soc. 1988, 110,4228423 1. (14) Ma, A. L.;Thoden, J. B.; Dahl, L. F. J. Chem. Soc.. Chem. Commun. 1992, 1516-1518. (1 5) Coucouvanis,D.;Patil, P. R.;Kanatzidis, M. G.; Detering, B.; Baenziger, N. C. Inorg. Chem. 1985, 24, 2431. (16) Fcnske, D.; Ohmer, J.; Hachgenei, J.; Mcrzweiler, K. Angew. Chem., Inr. Ed. Engl. 1988, 27, 1277-1296. (17) Lee,S. C.; Holm, R. H. J. Am. Chem. Soc. 1990, 112,9654-965s. (18) Chau, C.-N.; Wardle, R. W. M.; Ibers, J. A. Inorg. Chem. 1987, 26, 274&2741. (19) Fedin, V. P.; Mironov, Y. V.;Sokolov, M. N.; Kolesov, B. A.; Fedorov, V. Y.; Yufit, D. S.;Struchkov, Y . T. Inorg. Chim. Acra 1990, 174, 275-282.
0020-166919311332-3923$04.00/0
[M3S(S2),X6]"
+ 3SePPh,
-
[M3S(SSe)3X6]z-+ 3Ph3PS (1) Is this a general reaction among soluble metal chalcogenides? Since TePPh3 does not exist, we initiated reactivity studies of TePEt3 with selenometalates, anticipating success in converting selenides to tellurides in the Ni triad because stable tellurides of that triad, i.e. [Ni4Te4(Te2)2(Tes)4)'lm and [Pd(Te4)2]2-,21,22 have been prepared by other routes. We chose [Ni(Se4)2I2-l 1 and [Pt(Se4)3]2-23 as starting materials owing to their structural simplicity and ease of preparation. We expected to prepare [Ni(Te&]2- and [Pt(Te&]Z-. Not only was substitution of Se by Te successful but also structural rearrangement occurred to afford the [PP~,I~[N~T~~(T~z)z(T~~)~I and [PPh,l4[%Te4(Te3)d cubanes. This paper reports this chemistry as well as the synthesis of [NEt4]4[Pt4Te4(Te3)6] by a different route.
Experimental Section All manipulations were carried out under N2 with the use of standard Schlenk-line techniques. Solvents were distilled, dried, and degassed before use. Elemental analyses were performed by Oneida Research Services, Whitesboro, NY, and G. D. Searle & Co., Skokic, IL. Li2Te was prepared from the stoichiometric reaction of Li and Te in liquid NH3. [Ni(Se4)2]*-,I1 [Pt(Se4)3l2-,Z3 Pt(xan)2,2' and TePEt325 were prepared by published methods. Preparation of [PPhrUNi4Tq(Te2)2(Te3)4] (1). TePEt3 (197 mg, 0.8 mmol) dissolved in 5 mL of D M F was added to a solution of [PPl~&[Ni(Se4)2] (137 mg, 0.1 "01) in 5 mL of DMF. The solution was stirred for 2 h and filtered. Next toluene (15 mL) was layered on top of the filtrate. Black crystals of 1 formed overnight (16 mg, 16% yield). Anal. Calc for C~H80P4Ni4Te2o:C, 27.82; H, 1.95; P, 2.99. Found: C, 27.45; H, 1.88; P, 2.79. McConnachie, J. M.; Ansari, M. A.; Iben, J. A. Inorg. Chlm. Acta 1992,198-200, 85-93.
Adams, R. D.; Wolfe, T. A.; Eichhom, B. W.; Haushalter, R. C. Polyhedron 1989, 8, 701-703. Kanatzidis, M. G. Acra Crysrallogr. 1991, C47, 1193-1 196. Ansari, M. A.; Ibcrs, J. A. Inorg. Chem. 1989,28,40684069. Watt, G . W.; McCormick, B. J. J. Inorg. Nucl. Chem. 1%5,27, 898900.
Zingaro, R. A,; Steeves, B. H.; Irgolic, K. J. Organmet. Chcm. 1965, 4, 320-323.
0 1993 American Chemical Society
3924 Inorganic Chemistry, Vol. 32, No. 18, 1993
McConnachie et al.
Table I. Crystallographic Details [PPh414[Ni4Te201( 1)
[NEt414[PtrTenI. ZDMF(3) formula CwH~oP4Ni4Te20 C~~H~~N~OZP~~T~ZZ fw 4255 4144 15.685(3) 18.925(3) a, A 40.103(8) 18.925(3) b, A 15.330(3) 17.155(3) c, A 119.10(3) 90.00 %t deg v,A3 8426(3) 6 144(2) 4 Z 2 d(calcd), g/cm3 3.354 2.240 space group DLPan2 G-P21Ic 1, o c -163 -163 A. A 0.7093 IMo Kail 0.7093 IMo Kail Figure 1. The [Ni4Te4(Te2)2(Te3)4IC cubane in [PPh]r[Ni4Te4p, cm-' 53.6 142.1 (Te2)2(Te3)4] (1). The cubane lies on a 4 axis. In this and succeeding transm coeff 0.557-0.645 0.051-0.464 figures the 50% probability ellipsoids are shown. 0.066 R(Fo) (Foz > 2u(FO2))" 0.062 Rw(Fo2)(all data) 0.143 0.136 Table IV. Cubane Bond Distances (A) and Angles (deg) for The threshold Fo2> 2u(FO2)was used only for computing R on F,; [PPh414[Ni4Te4(Te2)2(Te3)41 (1) all data were used in the refinement and in computing R on Fo2. Ni-Ni( a) 3.611(4) Te(1)-Ni-Te(l1) 95.79(13) Ni-Ni( b) 3.826(4) Te( la)-Ni-Te( 11) 78.12(11) Te(1)-Te(1a) 3.447(4) Te( 1b)-Ni-Te( 11) 160.7(2) Te( 1)-Te( 1b) Table 11. Cubane Atomic Positions and Equivalent Isotropic 3.336(4) Te(l)-Ni-Te(Zl) 93.42(13) Ni-Te( 1) 2.536(4) Te(1a)-Ni-Te(21) Thermal Parameters for [PPh414[NbTe4(Te2)2(Tea)4](1) 175.8(2) Ni-Te( la) 2.489(4) Te(1b)-Ni-Te(21) 101.58(13) atom X Y Z u,," A2 Ni-Te( 1b) 2.565(4) Te(l)-Ni-Te(23a) 168.9(2) Ni-Te( 11) 2.614(4) Te(la)-Ni-Te(23a) 98.08(13) Ni -0.961 6(2) 0.087 3(2) -0.083 O(2) 0.045(2) Ni-Te(2 1) 2.577(4) Te(1b)-Ni-Te(23a) 88.90(12) Te(1) -0.917 35(9) -0.038 25(10) -0.066 38(11) 0.0487(13) Ni-Te(23a) 2.543(4) Te( 1l)-Ni-Te(21) 97.69( 12) Te(l1) -1.002 59(10) 0.072 02(10) -0.227 55(11) 0.0586(14) Te(l1)-Te(l1a) 2.728(4) Te(1 l)-Ni-Te(23a) 95.04(12) Te(21) -0.837 24(10) 0.136 71(10) -0.111 15(12) 0.0552(13) Te(2 1)-Te(22) 2.728( 3) Te(2 l)-Ni-Te(23a) 82.63(11) Te(22) -0.777 86(10) 0.134 79(11) 0.033 75(12) 0.0599(13) Te(22)-Te(23) 2.777(3) Ni-Te(l1)-Te(l1a) 95.75(9) Te(23) -0.782 24(9) -0.006 96(10) 0.075 25(11) 0.0519(11) Ni-Te(2 1)-Te( 22) 101.58(11) a U , = '/3CiZj(Utj~*ia*praj). Te( 1)-Ni-Te( la) 86.63(12) Ni(b)-Te(23)-Te(22) 105.59(11) Te( 1)-Ni-Te( 1b) 81.69(12) Te(21)-Te(22)-Te(23) 103.54(9) Table III. Cubane Atomic Positions and Equivalent Isotropic Te( 1a)-Ni-Te( 1b) 82.60( 12) Thermal Parameters for [NEt&[PtrTe4(Te&].2DMF (3) Ni-Te( 1)-Ni(a) 91.89(12) Ni-Te( 1)-Ni( b) 97.19(13) atom X Y z u, A2 Ni(a)-Te( 1)-Ni(b) 98.40(12) 0.331 58(3) 0.786 55(6) 0.0203(4) 0.133 85(5) Pt(1) 0.0227(4) 0.377 38(3) 0.664 55(6) Pt(2) 0.270 42(6) crystals of 3 formed overnight (159 mg, 30% yield). Anal. Calc for 0.329 73(2) 0.918 51(6) 0.0198(4) Pt(3) 0.419 89(5) C38H94N602&Te22: C, 10.73; H, 2.23; N, 1.98. Found C, 10.34; H, 0.411 95(3) 0.908 45(7) 0.0249(4) Pt(4) 0.282 63(6) 2.19; N, 1.75. 0.317 92(4) 0.738 43(10) 0.0206(6) Te(1) 0.271 22(9) CrystallographicStudies. Intensity data for 1-3 were collected from 0.392 41(4) 0.731 28(10) 0.0220(7) Te(2) 0.147 23(9) 0.348 75(4) 0.959 46(10) 0.0214(6) single crystals with the use of an Enraf-Nonius CAD4 diffractometer. Te(3) 0.284 40(9) Te(4) 0.404 18(10) 0.391 ll(4) 0.847 83(10) 0.0228(7) Acrystalstructuredeterminationof2wasdeemedunlikely tobesuccessful, Te(l1) -0.022 13(10) 0.316 18(5) 0.611 35(11) 0.0283(7) not only because the crystals were of marginal quality as judged by the Te(12) 0.061 35(11) 0.304 lO(5) 0.493 21(11) 0.0332(8) falloff of intensity with scattering angle but also because they belong to Te(13) 0.121 53(10) 0.366 44(5) 0.480 66(11) 0.0313(8) the trigonal system, generally a bad omen for complex materials. Te(21) 0.116 33(10) 0.267 89(4) 0.828 24(11) 0.0267(7) Nevertheless, we persisted with data collection since at that time crystals Te(22) 0.277 26(11) 0.252 71(5) 1.005 72(11) 0.0303(8) of 3 were unavailable. Data from the three compounds were processed Te(23) 0.422 73(10) 0.265 23(4) 0.960 88(12) 0.0278(7) by methods standard in this laboratory26 and then corrected for Te(31) 0.00467(10) 0.343 97(5) 0.849 22(11) 0.0295(7) abs~rption.~'The positions of the heavy atoms of all three structures Te(32) -0.011 13(11) 0.412 26(5) 0.844 05(12) 0.0360(8) werelocated with the SHELXS86ZB direct-methodsprogram;thesmctures Te(33) 0.171 25(12) 0.430 74(5) 0.987 21(12) 0.0355(9) were refined on P with the SHELXL-9229least squares program, and Te(41) 0.408 50(11) 0.364 73(5) 0.614 72(11) 0.0347(8) the results were analyzed with the SHELXTL PC30 graphics programs. Te(42) 0.466 86(10) 0.301 56(5) 0.681 63(12) 0.0333(7) In 1 the heavy atoms could be refined anisotropically but some of the Te(43) 0.565 53(10) 0.31097(5) 0.883 25(11) 0.0287(7) light atoms could not. Consequently, in the final model all light atoms Te(S1) 0.265 57(12) 0.438 99(5) 0.589 28(13) 0.0420(10) were refined isotropically. Our fears for the structureof 2 wereconfirmed: Te(52) 0.372 18(13) 0.477 22(5) 0.755 07(15) 0.0489(11) the PPh4+ cations could not be located; only the atoms of the anion were Te(53) 0.257 83(14) 0.474 28(5) 0.843 25(15) 0.0459(11) Te(61) 0.572 93(10) 0.346 73(5) 1.093 62(11) 0.0298(7) located and refined anisotropically,except for atoms Te(22) and Te(24), Te(62) 0.501 SO(11) 0.382 88(5) 1.192 79(11) 0.0364(8) which are disordered and which were refined isotropically. As the data Te(63) 0.429 63(12) 0.437 93(5) 1.074 63(13) 0.0405(9) merged to Rbt = 0.06 when anomalousdispersion effectsweredisregarded, the problem with the structure of 2 is not with the intensity data,but most likely with disorder and twinning (actually trilling), which is common in Preparationof [PPluMfiTe4(Tej)s] (2). TePEt3 (296 mg, 1.2 "01) dissolvedin 5 mL DMF was added to a solution of [PPh&[Pt(Se4)3].DMF the trigonal system. In 3 all non-hydrogen atoms were refined ani* (189 mg, 0.1 mmol) dissolved in 5 mL of DMF. The solution was stirred for 2 h and filtered. Next toluene (15 mL) was layered on top of the (26) Waters, J. M.; Ibers, J. A. Inorg. Chem. 1977, 16, 3273-3277. filtrate. Black crystals of 2 formed overnight (31 mg, 26% yield). Anal. (27) de Meulenaer, J.; Tompa, H. Acra Crysrallogr. 1965,19, 1014-1018. (28) Sheldrick, G. M. In Crystallographic Computing 3; Sheldrick, G. M., Calcfor CwH~oP4PbTe22:C, 23.32; H, 1.63; P, 2.51. Found: C, 22.65; Kriiger, C., Goddard,R., Eds.; Oxford University Press: London, 1985; H, 1.41; P, 2.44. pp 175-189. Prepara~of[NE4]rSfiTq(Tg)cl.2DMF(3). AmixtureofPt(xan)2 (29) Sheldrick, G. M.SHELXL-92 Unix Beta-test Version. (218 mg 0.5 mmol), Li2Te (212 mg, 1.5 mmol), Te(383 mg, 3 mmol), (30) Sheldrick, G. M. SHELXTL PC Version 4.1: An integrated system for and N E W 1 (166 mg, 1 "01) in DMF (30 mL) was stirred for 2 h and solving,refining,and displaying crystal structuresfrom diffraction data, filtered. Next ether (60 mL) was layered on top of the filtrate. Black Siemens Analytical X-Ray Instruments, Inc., Madison, WI. "pd
~~
~~
Inorganic Chemistry, Vol. 32, No. 18, 1993 3925
Chalcogenide Substitution Reactions
Figure 2. Stereoview of the [NiTe4(Tez)z(Te3)4]' cubane in [PPL]~[N~T~~(T~z)z(T~~)~] (1). 1
3
11
12
4Pt(xan),
Figure 3. The [Pt4Te4(Teo)6lC cubane in [NEt&[Pt4Te4(Te&] (3). tropically, except atom C(34), which could only be refined isotropically. Prior to the final refinements of 1 and 3, hydrogen atoms were included at calculated positions. Some crystallographicdetails are listed in Table I. The final positional parameters and equivalent isotropic thermal parameters for the cubane portions of 1 and 3 are given in Tables I1 and 111, respectively. Additional crystallographic details and results (including those for 2) are given in Tables S I S X . 3 1
RWults Syntheses. Surprisingly, the reactions of [Ni(Se4)2I2-l 1 and [Pt(Se4)3I2-23 with TePEtP do not afford the corresponding [M(Te4),,I2-species, but rather provide convenient routes to the NilV and PtIV tellurocubanes, [Ni4Te4(Tez)2(Te3)4l4 and [Pt4TedTe3)614-:
-
4[PPh412[Ni(Se4),] + 32TePEt3 [PPh,] [Ni,Te,(Te,),(Te,),] + 32SePEt3 + 2" [PPh,] 2Te6n (2)
+
ligands seem more likely in view of the partial substitution of S for Se and the presence of a SSe" ligand in an earlier rea~ti0n.I~ Previously, we reported the synthesis of the NEt4+ salts of [NbSe4(Se3)5(Se4)]' and [Ni4Te4(Tez)z(Te3)4]4-.50.32 Thesesalts are isolated from the reaction of Ni(xan)2 with polyselenide or polytelluride in DMF. The synthesis of [PPh4]4[Pt4Te4(Te3)6] (2), crystals of which were invariably of dismal txystallographic value, encouraged us to bypass this chalcogensubstitutionreaction and attempt the synthesis of [NEh] [Pt4Te4(Te&] by the polytelluride route in the hope that better crystals could be obtained with a different cation. Indeed, the reaction of Pt(xan)z with polytelluride in DMF yields 3:
-
4[PPh4l2[Pt(Se,),] 48TePEt3 [PPh,],[Pt,Te,(Te,),] + 48SePEt3 + 2"[PPh4],Te,3" (3) We previously reported the synthesis of [NEt4]4[Ni4Ted(Te2)2(Te3)4Iz0by a different route. This result strongly suggests that the [Ni4Te4(Te&(Tes)4]'anion, one of many possible anions of general formula [N&Te4(Te2),,(Te3)6]", is the thermodynamic product in these reactions. The synthesis of 1 requires oxidation of Nil1to NiIVwith concomitant reduction of Se or Te. The crystals from these reactions were analyzed by EDAX (electron dispersive analysis by X-ray), and the Se content was judged to be less than 1%. If less than a stoichiometric amount of TePEt3 was used, the resulting product was found to contain residual Se in addition to Te. As the amount of TePEt3 was increased, the ratio of Te to Se in the final product also increased. We have no direct evidencefor a mixture of materials rather than speciescontaining both Se and Te, although species containing mixed (Se/Te),,2-
-
+ 6Li,Te + 16Te + 4[NEt4]C1 [NEt4]4[Pt4Te4(Te3)6] + 8Li(xan) + 4LiC1 (4)
Both 1 and 2 are insoluble in common organic solvents. They may exist in equilibrium with other Ni-Te and Pt-Te anions, such as [Ni(Te4)#- and [Pt(Te4)3I2-, and crystallize out preferentially owing to their low solubility. Crystals of 3dissolve in DMF, but attempts to obtain Ig5Ptand lz5TeNMR spectra were unsuccessful. The anion appears to be unstable in solution. The brown color of 3 dissolved in DMF slowly turns to the redpurple of polytelluride, and Te is deposited on the sides of the NMR tube. Structure of [PPhrk[N4Tes(Ta)2(Te3)4](1). The crystal structure of 1 consists of well-separated cations and anions. The one crystallographically independent P P b + cation shows the expected geometry around the P center with a mean P-C bond length of 1.83(2) A and C-P-C angles ranging from 107.6(15) to 112.6(16)O. The mean C-C bond is 1.38(9) A, and the C-C-C anglesrangefrom 105.9(55) to 124.2(47)0,withamedianC-C-C angle of 119.8(39)O and a mean of 118.7(40)O. The P-C-C angles range from 115.7(33) to 122.0(30)O. More details are available in Table SVIII.31 The [Ni4Te4(Te2)2(Te3)4I4 anion, which has crystallographically imposed 4 symmetry, is shown in Figure 1 and 2. Bond distances and angles are summarized in Table IV. This [Ni4Te4(Te2)2(Te3)4I4 anion in the PPh4+ salt, though more symmetric owing to the imposed 4 symmetry, is almost identical to the same anion in the NEt4+ salt.20 Magnetic susceptibility and lz5TeNMR measurements on the NEh+ salt indicate that the salt is diamagnetic, and hence the Ni atoms have a d6electron configuration and are formally N P . In the present anion the Ni atom is in a distorted octahedral environment comprising three TeZ-ligands, which make up the other vertices of the cube, two Te32- ligands, and one TeZ2- chain, which bridges a face of the cube between the Ni atoms. Among Ni-Te distances the NiTe(1 l) distance of 2.614(4) A is the longest, the others ranging from 2.489(4) to 2.577(4) A. As anticipated for a species containing NilVthe Ni-Ni distances at 3.61 l(4) and 3.826(4) A are too long for bonding interactions. The Te chains distort the cubane core, the TesZ-ligands causing the larger deviations from (32) McConnachie, J. M.; Ansari, M. A.; Ibers, J. A. J . Am. Chem. Soc.
(31) Supplementary material.
1991,113, 7078-7079.
McConnachie et al.
3926 Inorganic Chemistry,Vol. 32, No. 18. 1993
Figure 4. Stereoview of the [hTe4(Tea)6l4 cubane in [NEb]4[hTe4(Te3)6](3).
Table V. Cubane Bond Distances (A) and Angles (deg) for [NEt4]4[hTe4(Tea)s].ZDMF(3)
Pt(l)-Pt(2) Wl)-Pt(3) Pt(1 )-Pt(4) Pt(2)-Pt(3) Pt(2)-Pt(4) Pt(3)-Pt(4) Te(1)-Te(2)
Te(1)-Te(3) Te( 1)-Te(4) Te(2)-Te(3)
Te(2)-Te(4) Te(3)-Te(4)
Te( 1)-Pt( 1)-Te(2) Te(1)-Pt(l)-Te(3) Te(2)-Pt( 1)-Te(3) Te(1)-Pt(2)-Te(2) Te(1)-Pt(2)-Te(4) Te(2)-Pt(2)-Te(4)
Te(1)-Pt(3)-Te(3) Te( l)-Pt(3)-Te(4) Te(3)-Pt(3)-Te(4)
Te(2)-Pt( 4)-Te( 3) Te(2)-Pt( 4)-Te(4) Te(3)-Pt(4)-Te( 4) Pt( 1 )-Te(1)-Pt(2) Pt( 1)-Te( 1)-Pt(3) Pt(2)-Te( 1)-Pt(3)
Pt( l)-Te(Z)-Pt(2) Pt(1)-Te(2)-Pt(4) Pt(2)-Te(2)-Pt(4)
Pt( 1)-Te(3)-Pt(3) Pt( 1)-Te(3)-Pt(4) Pt(3)-Te(3)-Pt(4) Pt(2)-Te(4)-Pt( 3) Pt( 2)-Te(4)-Pt(4) Pt( 3)-Te( 4)-Pt(4)
3.919(2) 3.924(2) 3.884(2) 3.928(2) 3.904(2) 3.900(2) 3.537(2) 3.517(2) 3.5 18(2) 3.551 (2) 3.526(2) 3.531(2) 84.20(5) 83.24(5) 84.78(6) 83.82(5) 84.00(6) 83.83(5) 84.02(5) 83.13(6) 84.38(6) 84.66(6) 84.28(5) 83.97(6) 95.62(6) 95.49(5) 95.96(6) 95.78(6) 95.44(6) 95.28(5) 96.76(5) 94.43(6) 95.84(6) 96.31(6) 96.07(5) 95.15(6)
Pt(1)-Te(l1) Pt( 1)-Te(21) Pt(1)-Te(31) Pt(2)-Te( 13) Pt(2)-Te(4 1) Pt(2)-Te(5 1) Pt(3)-Te(23) Pt(3)-Te(43) Pt(3)-Te(6 1) Pt(4)-Te(33) Pt(4)-Te( 53) Pt(4)-Te(63)
Te(1)-Pt(1)-Te(l1) Te(1)-Pt(1)-Te(21) Te(1)-Pt( 1)-Te(3 1) Te(2)-Pt(1)-Te(l1) Te(Z)-Pt(l)-Te(2l) Te(2)-Pt( 1)-Te(31) Te(3)-Pt(l)-Te(ll) Te(3)-Pt( 1 )-Te(2 1 ) Te(3)-Pt( 1)-Te(3 1) Te(1)-Pt(2)-Te( 13) Te( l)-Pt(2)-Te(41) Te(l)-Pt(2)-Te(5 1) Te(Z)-Pt(l)-Te( 13) Te(2)-Pt(2)-Te(4 1) Te(Z)-Pt(Z)-Te(5 1) Te(4)-Pt(2)-Te( 13) Te(4)-Pt(2)-Te(4 1 ) Te(4)-Pt(2)-Te(51) Te(l)-Pt(3)-Te(23) Te( 1)-Pt(3)-Te(43) Te( 1)-Pt(3)-Te(61) Te(3)-Pt(3)-Te(23) Te(3)-Pt( 3)-Te(43) Te(3)-Pt(3)-Te(6 1)
2.681(2) 2.679(2) 2.677(2) 2.681(2) 2.672(2) 2.712(2) 2.662(2) 2.698(2) 2.677(2) 2.670(2) 2.650(2) 2.679(2) 98.20(5) 93.49(6) 175.68(6) 93.90(6) 175.44(6) 97.85(6) 177.94(6) 98.88(6) 93.14(5 ) 97.09(6) 96.66(6) 178.49(6) 90.99(5) 174.24(6) 94.69(6) 174.57(6) 90.5l(5) 96.14(7) 88.99(6) 98.24(5) 174.80(7) 98.31(6) 177.72(6) 97.04(5)
cubic symmetry. These and other geometric features of the [Ni4Te4(Te&(Te3)4lb anion have been discussed previously.20 Structure of [PPhMmTe4(Te&] (2). Information on this structure may be found in the supplementary material. The same anion is much better defined in 3. Structure of [NEt4]d&Te4(Te3)sE2DMF (3). The crystal structure of 3 consists of the packing of well-separated cations and anions and DMF solvent molecules. The four independent NEb+ cations have their expected geometries as do the two independent DMF molecules. The mean N-C and C-C bond lengths in the NEt4+ ions are 1SO(2) and 1.56(6) A, respectively, and the C-N-C and N-C-C angles range from 101.5(24) to 115.8(20)O and from 107.3(24) to 118.9(21)O, respectively. The DMF molecules have mean N-C and 0-C distances of 1.39(5) and 1.21(1) A, respectively, C-N-C angles ranging from 118.4(23) to 122.2(36)O, and N-C-O angles of 124.2(35) and 129.4(49)O. Further details are available in Table SX.31 The [&Te4(Te&l4anion with atomlabels is shown in Figure 3, and a stereoview is shown in Figure 4. Metrical data for the anion are given in Table V. Each Pt atom has a slightly distorted octahedral coordination, being bound to three Te2- ligands that
Pt(1)-Te(1) Pt(1)-Te(2)
Pt(1)-Te(3) Pt(2)-Te( 1) Pt(2)-Te(2) Pt(2)-Te( 4) Pt(3)-Te( 1) Pt(3)-Te(3) Pt(3)-Te( 4) Pt( 4)-Te( 2) Pt(4)-Te(3) Pt(4)-Te(4) Te(4)-Pt( 3)-Te(23) Te(4)-Pt(3)-Te(43) Te(4)-Pt(3)-Te(6 1) Te(2)-Pt( 4)-Te( 33) Te(2)-Pt( 4)-Te( 5 3) Te(Z)-Pt(4)-Te( 63) Te(3)-Pt( 4)-Te( 33) Te(3)-Pt(4)-Te( 53) Te(3)-Pt(4)-Te(63) Te(4)-Pt(4)-Te(33) Te(4)-Pt( 4)-Te( 5 3) Te(4)-Pt(4)-Te(63) Te(l1)-Pt(1)-Te(21) Te(1 l)-Pt(l)-Te(31) Te(21)-Pt(l)-Te(31) Te(13)-Pt(2)-Te(41) Te(13)-Pt(2)-Te(51) Te(4l)-Pt(Z)-Te(S 1) Te(23)-Pt(3)-Te(43) Te(23)-Pt(3)-Te(6 1) Te(43)-Pt(3)-Te(6 1 ) Te(33)-Pt(4)-Te(53) Te(33)-Pt(4)-Te( 63)
2.652(2) 2.624(2) 2.643(2) 2.637(2) 2.658(2) 2.620(2) 2.650(2) 2.606(2) 2.652(2) 2.625(2) 2.649(2) 2.631(2) 1 71.38( 6) 95.53(6) 91.90(6) 1 OO.02(6) 89.70(7) 171.48(7) 92.97(6) 173.07(6) 102.17(6) 174.49(6) 99.51(6) 91.32(6) 82.52(6) 85.47(5) 84.72(6) 94.65(6) 82.64(6) 84.85(6) 82.1l(6) 95.88(6) 80.69(5) 84.04(7) 84.84(6)
Te(l1)-Te(l2) Te( 12)-Te( 13) Te(21)-Te(22) Te(22)-Te(23) Te(3 1)-Te(32) Te(32)-Te(33) Te(41)-Tc(42) Te(42)-Te(43) Te(5 1)-Te(52) Te(52)-Te(53) Te(61 )-Te(62) Te(62)-Te(63)
Te(53)-Pt(4)-Te(63) Pt( 1)-Te(1 1)-Te(12) Pt(2)-Te(l3)-Te( 12) Pt(1 )-Te(21)-Te(22) Pt(3)-Te( 23)-Te( 22) Pt( l)-Te(31)-Te(32) Pt(4)-Te( 33)-Te(32) Pt(2)-Te(41)-Te(42) Pt(3)-Te(43)-Te(42) Pt(Z)-Te(Sl)-Te( 52) Pt(4)-Te( 53)-Te( 52) Pt(3)-Te(6 1 )-Te(62) Pt(4)-Te(63)-Te(62) Te(1 l)-Te(12)-Te(13) Te(21 )-Te(22)-Te( 23) Te(3 l)-Te(32)-Te(34) Te(4 1 )-Te(42)-Te(43) Te(5 1 )-Te(52)-Te( 53) Te(6 l)-Te(62)-Te(63)
2.745(2) 2.712(3) 2.732(2) 2.731(2) 2.748(3) 2.728(3) 2.719(3) 2.727(2) 2.733(3) 2.723(3) 2.706(2) 2.728(3) 83.82(7) 101.88(6) 103.38(7) 107.32(7) 108.86(7) 104.36(7) 102.73(7) 103.88(7) 101.33(6) 103.74(7) 102.52(8) 106.59(6) 101.73(8) 100.27(8) 100.88(7) 101.71(8) 101.54(8) 100.63(8) 102.17(7)
make up the other vertices of the cube and three Tep2-chains that bridge the faces of the cube between the Pt atoms. The mean Pt-Pt distance is 3.910(17) A and the mean Te-Te distance is 3.530( 13) A in the core. The Te-Pt-Te angles in the cube range from 83.13(6) to 84.78(6)' compared to the Te-Ni-Te angles of 81.69(12) and 82.60(12)Oin the [NbTe4(Tez)z(Te3)4]'anion; thePt-Te-Ptanglesin thecuberangefrom94.43(6)to96,76(5)O compared with Ni-Te-Ni angles of 97.19( 13) and 98.4O( 12)O. The Tes2- ligands are unremarkable and differ little from those in the Ni cubane; the pseudo F't2Te3 five-membered rings have the envelope conformation. The [Pt4Te4(Te3)6l6 cubane is an analogue of the [Re& (S3)#-~cubane~~ and a variant of the [Ni4Se4(Se3)s(Se4)lc and [Ni4Te4(Te&(Te&]' ~ubanes.~O*~~ All these cubanes contain MIv centers, unexceptional for Pt and Re and exceptionalfor Ni. Since the [Pt4Te4(Te&]' anion has been prepared by two different routes and crystallized with two different cations, it again appears to be the thermodynamicallystable species. Why (33) Maller, A.;Krickemeyer,E.;B6gge, H.Angew. Chem., Znt. Ed. Engl. 1986,25, 212-213.
Chalcogenide Substitution Reactions then do we find [Pt4Te4(Te3)6Jk but [Ni4Te4(Tez)2(Te3)4lk? The lengthening of the M-Te bond on going from Ni to Pt might help accommodate the Te3- ligand that greatly distorts the NidTe4 core in 1. Alternatively, the relative hardness of the ligand and metal center may dominate the ligand selection. A formal NirV center is a hard acid; a P t I V center is softer. The TeZ2-ligand has its negative charge spread over fewer atoms than does the Te32ligand and thus should be a harder base. Consequently,the TeZ2ligand might stabilize NiIV.
Discussion We have demonstrated here the utility of chalcogenide substitution and rearrangement in the synthesis of new metal chalcogenide species. The driving force for chalcogenide substitution is presumably the relative strength of the Q-PR3 bond, which is S-P > Se-P > Te-P. If the reaction is general, then TePR3 should react with soluble metal sulfides and selenides, and SePR3 should react with metal sulfides. Hence, all known sulfidometalates would be potential precursors for seleno- and tellurometalates, and all known selenometalates would be precursors for tellurometalates. In fact, depending on M-0 and 0-P versus M-Q and Q-P bond strengths, oxides might also succumb to phosphine chalcogenide substitution. Three important factors for chalcogen substitution are the strength of M-Q bonds, the position of Q in a metal complex, and the phosphine basicity. (The phosphine chalcogenides are conveniently made by heating the phosphineand elemental chalcogen in so obviously the formation of Q-P versus Qbonds is not an important factor.) Various metals may form M-Q bonds that are too strong for chalcogen substitution to proceed fully. Chalcogen atoms may occupy different positions, e.g. terminal, bridging, and ring, within metal chalcogenidespecies and exhibit differing reactivities as a result of differing steric and electronic factors. And, of course, different phosphine chalcogenides will form Q-P bonds of different strengths, thus influencing the course of a chalcogen substitution reaction. When these factors are understood, phosphine chalcogenides should provide routes to seleno- and tellurometalates in systems where none currently exists, such as those with M = Re, Rh. While the differing thermodynamic and steric properties of the chalcogenide ligands may cause structural rearrangement during chalcogenide substitution, as in the reactions leading to 1 and 2 above, structural integrity may be retained and compounds common to all three
Inorganic Chemistry, Vo1.32, No. 18, 1993 3927 chalcogens may be isolated. For example, we have found that structural integrity is maintained in the reaction of TePEt3 with the [M(Se4)2I2- anions of the Zn triad.34 In soluble metal chalcogenide systems with isostructural S,Se, and Te complexes, such as [Hg(Q4)2]2-,11J4.35 all possible combinations could ideally be isolated. Chalcogenide substitution reactions may also lead to greater variability in the length of Se and Te chains. The most common Qnz-length is n = 4 in Se and Te complexes, but n > 4 is common for S.35If one were to start from sulfidometalates having n > 4, Se and Te chains of n > 4 might be obtained. The growing i n t e r e ~ t I ~in*mixed ~ ~ . ~chalcogenide ~ ligands will be well served by chalcogen substitution reactions. Even if a metal species does not substitute its chalcogens completely, the promise of novel mixed species is always present. If these new species follow the concept of topological charge stabilization,3* as the recent work with heteropolychalcogenide anions sugg e s t ~ ? ~ judicious - ~ ~ , ~use ~ .of~ a~phosphine chalcogenide reagent could produce compounds with different chalcogens in specific positions.
Acknowledgment. This research was supported by the National Science Foundation (Grant Nos. CHE-8922754 and CHE9224469). Supplementary Material Available: Further details of data collection and refinement (Table SI), cation atomic positions for 1 (Table SII), atomic positions and equivalent isotropic thermal parameters for the anion of 2 (Table SIII), cation and solvent atomic positions for 3 (Table SIV),thermal displacement parameters (Tables SV-!3VII), cation bond distances and angles for 1 (Table SVIII), anion bond distance and angles for 2 (Table SIX), and cation and solvent distances and anglcs for 3 (Table SX) (21 pages). Ordering information is given on any current masthead page. (34) McConnachie, J. M.; Ibers, J. A. Unpublished results. (35) Miiller,A.;Schimanski,J.;Schimanski,U.;Bcgge, H. 2.Natursforsch., B: Chem. Sci. 1985, 40, 1277-1288. (36) Bj6rgvinsson. M.; Schrobilgen, G. J. Znorg. Chem. 1991, 30, 25402547. (37) Bj&gvinsson, M.; Sawyer, J. F.; Schrobilgen,G. J. Znorg. Chem. 1991, 30.4238-4245. (38) Gimarc, B. M. J. Am. Chem. Soc. 1983,105, 1979-1984. (39) Huang, S.-P.; Dhingra, S.; Kanatzidis, M. G. Polyhedron 1992, 11, 1869-1875. (40) Zagler, R.; Eisenmann, B. Z . Naturforsch., B: Chem. Sei. 1991, 16, 593-601.
